Numerical Simulations of Collapsing, Isothermal, Magnetic Clouds

Abstract

In recent years, a number of numerical experiments have simulated various aspects of the early stages of star formation (see Tscharnuter 1980 for a discussion and review). In all but one of these experiments, however, the effects of the interstellar magnetic field have been neglected, although observations (for example, see Verschuur 1969) suggest that in some interstellar clouds, the magnetic energy is comparable to, or even greater than, the gravitational and thermal energies. It is also believed (Mouschovias 1981), that at least at the early, diffuse stages of collapse, where the ionizing radiation can penetrate deep into the cloud, the bulk of the neutral matter will feel the magnetic forces via collisional coupling with the ionized matter. Thus there exist no observational, nor theoretical reasons justifying the neglect of the interstellar magnetic field in these numerical simulations.